全文获取类型
收费全文 | 1623篇 |
免费 | 178篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 92篇 |
妇产科学 | 30篇 |
基础医学 | 148篇 |
口腔科学 | 38篇 |
临床医学 | 267篇 |
内科学 | 254篇 |
皮肤病学 | 32篇 |
神经病学 | 119篇 |
特种医学 | 38篇 |
外科学 | 312篇 |
综合类 | 63篇 |
一般理论 | 1篇 |
预防医学 | 155篇 |
眼科学 | 14篇 |
药学 | 123篇 |
中国医学 | 1篇 |
肿瘤学 | 106篇 |
出版年
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 22篇 |
2018年 | 27篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 35篇 |
2013年 | 40篇 |
2012年 | 54篇 |
2011年 | 63篇 |
2010年 | 37篇 |
2009年 | 34篇 |
2008年 | 63篇 |
2007年 | 73篇 |
2006年 | 77篇 |
2005年 | 85篇 |
2004年 | 59篇 |
2003年 | 62篇 |
2002年 | 67篇 |
2001年 | 52篇 |
2000年 | 60篇 |
1999年 | 56篇 |
1998年 | 30篇 |
1997年 | 32篇 |
1996年 | 37篇 |
1995年 | 39篇 |
1994年 | 29篇 |
1993年 | 35篇 |
1992年 | 50篇 |
1991年 | 44篇 |
1990年 | 31篇 |
1989年 | 43篇 |
1988年 | 38篇 |
1987年 | 31篇 |
1986年 | 35篇 |
1985年 | 23篇 |
1984年 | 19篇 |
1983年 | 17篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1979年 | 13篇 |
1974年 | 22篇 |
1973年 | 10篇 |
1972年 | 14篇 |
1971年 | 13篇 |
1970年 | 18篇 |
1968年 | 11篇 |
1966年 | 11篇 |
排序方式: 共有1815条查询结果,搜索用时 15 毫秒
91.
BACKGROUND: As little has been published on the course of idiopathic solar urticaria (SU) patients cannot receive comprehensive prognostic advice. OBJECTIVE: To determine the prognosis and photobiological characteristics of idiopathic SU. DESIGN: Historical cohort study, with inception cohort followed up from time of diagnosis. Follow-up for a median of 4 years (range, 3 months to 26 years) after diagnosis. SETTING: Tertiary referral center for the investigation of photodermatoses in Scotland. PATIENTS: The study included 87 patients, 61 (70%) of whom were female, with phototest-confirmed idiopathic SU between 1975 and 2000. Sixty patients (69%) were followed up clinically, and 25 patients (29%) were phototested on 2 or more occasions. INTERVENTIONS: Investigations at time of diagnosis included monochromator phototesting. Further monochromator phototesting was performed in those patients in whom it was clinically indicated (select subgroup), and all patients who could be traced received a follow-up questionnaire. MAIN OUTCOME MEASURES: Characteristics of SU, responsible wave bands, and prognosis for clinical resolution. RESULTS: The prevalence of idiopathic SU in Tayside, Scotland, is estimated to be 3.1 per 100 000. Action spectra were typically broad, with 63% reacting to more than 1 wave band, and the most common provoking wavelengths were the longer UV-A and the shorter visible ones. The majority of subjects were affected perennially (68%), by radiation transmitted through glass (83%) and thin clothing (76%). Coexistent polymorphic light eruption occurred in 20 patients (23%), and another photodermatosis occurred in 6 patients, 3 of whom had chronic actinic dermatitis. In those with SU alone, the mean age at onset was 41 years. The probability of clinical resolution at 5 and 10 years after diagnosis was 0.12 (95% confidence interval, 0.06-0.24) and 0.26 (95% confidence interval, 0.15-0.43), respectively. CONCLUSION: Idiopathic SU is a chronic disease. The majority of this cohort was still affected after 5 and 10 years. 相似文献
92.
93.
Key A George CL Beattie D Stammers K Lacey H Waller G 《The International journal of eating disorders》2002,31(2):185-190
OBJECTIVE: This pilot study examined the role of mirror confrontation in the desensitization process of a body image treatment within an inpatient program for anorexia nervosa. METHOD: A within-subjects design was used. It compared the impact of two modes of group body image treatment on body dissatisfaction, anxiety, and avoidance behaviors. Both treatments followed a set format of exposure exercises and homework, but the modified treatment also included mirror confrontation as an exposure exercise. RESULTS: Standard treatment did not produce any significant changes. Modified treatment produced a significant and sustained improvement in body dissatisfaction and a significant reduction in body anxiety and avoidance behaviors. DISCUSSION: Mirror confrontation is a more effective form of exposure because of the strong emotional response it elicits. Patients' pronounced emotional response to this exercise allowed easier identification of the affective and behavioral components of body dissatisfaction and more cogent links into a developmental body image timeline. 相似文献
94.
Islet transplantation as a procedure to induce insulin independence is still a long way from benefitting the population of
more than 1 million type 1 diabetic patients in the United States. In addition to the problems involved with immune suppression,
the most significant obstacle is a scarcity of human organs for transplantation. In 1999, only 5882 donated pancreases were
available, of which only 50% could be expected to produce islet yields suitable for clinical purposes. In this article, we
review various sources with the potential to provide tissue for transplantation. These sources include islet and nonislet
cells derived from both human and nonhuman sources, with an emphasis on human cells. 相似文献
95.
Cosmetic camouflage advice improves quality of life 总被引:5,自引:0,他引:5
BACKGROUND: The subjective benefit of attendance at cosmetic clinics has not previously been reported. OBJECTIVES: To assess the effect on perceived quality of life (QoL) of cosmetic camouflage advice. METHODS: In a three-centre study, 135 individuals were invited to complete a dermatology-specific QoL measure, the Dermatology Life Quality Index (DLQI), before and 1 month after their first visit to a cosmetic camouflage clinic. RESULTS: Eighty-two completed DLQI questionnaires were returned before the camouflage clinic appointment, and 56 corresponding questionnaires were returned 1 month after. The mean age of responders was 50 years, and the mean duration of their skin conditions was 15 years. The main conditions seen were pigmentary disorders (29%), scars (22%) and vascular disorders (13%). There was a significant difference in mean DLQI scores before and after the clinic visit (9.1 vs. 5.8, P = 0.0001). CONCLUSIONS: When assessed at 1 month, attendance at a cosmetic camouflage clinic appears to improve QoL significantly. 相似文献
96.
Beattie GC Mason J Swan D Madhavan KK Siriwardena AK 《Scandinavian journal of gastroenterology》2002,37(12):1449-1453
BACKGROUND: Surgery for pancreatic necrosis complicating acute severe pancreatitis carries a high risk of mortality and may be influenced by a range of variables including patterns of referral, case selection and quality of care. METHODS: An observational study of a consecutive series of 54 patients undergoing pancreatic necrosectomy in a specialist Hepatobiliary unit over an 8-year study period. Principal outcomes were organ dysfunction and physiological derangement in relation to surgery, microbial colonization of necrosis and relation to outcome, re-operation rates, requirement for peri-operative nutritional support, trends in mortality and survival analysis. RESULTS: Necrosectomy was associated with statistically significant deterioration in immediate postoperative organ dysfunction scores (ANOVA P < 0.01). Infected necrosis was present in 36 (68%). Fungal colonization of necrosis was present in 5 (9%). Mortality in this subgroup was 80% (4 deaths). There was no association between bacterial colonization of necrosis and death in this study (P = 0.77; Fisher exact test; relative risk 0.9,95% confidence interval 0.54-1.54). Twenty patients (37%) required further surgical intervention with an average of 1.5 surgical procedures per patient. Twenty-three patients (43%) died. Patient survival to discharge was best predicted by admission APACHE-II score with relative risk of death increasing 14% for each unit increase in APACHE-II score at admission. CONCLUSIONS: The results of the present study illustrate that there is no place for complacency in the surgical management of patients with severe acute pancreatitis. A clinical governance approach would promote pre-defined protocols between admitting hospitals and tertiary referral centres. Future research should target new interventions in patients with high admission APACHE-II scores in whom prognosis is particularly poor and explore the role of infection of necrotic tissue. 相似文献
97.
Beattie C 《Anesthesiology Clinics of North America》2000,18(3):515-25, v-vi
It has been widely suggested that the specialty of anesthesiology should alter its traditional focus on the technical aspects of intraoperative care toward an expansion of its responsibilities and promotion of the profession as the practice of perioperative medicine. At Vanderbilt University School of Medicine, a program and a practice of perioperative medicine is being developed that reflects the expectation that such activity constitutes appropriate evolution of the profession, improves patient care, improves specialty image, and increases the ability to attract high-quality house-staff. 相似文献
98.
Postoperative cardiac morbidity and mortality continue to pose considerable risks to surgical patients. Postoperative epidural analgesia is considered to have beneficial effects on cardiac outcomes. The use in high-risk cardiac patients remains controversial. No study has shown that postoperative epidural analgesia decreases postoperative myocardial infarction (PMI) or death. All studies are underpowered to show such a result, and the cost of conducting a large trial is prohibitive. We performed a metaanalysis to determine whether postoperative epidural analgesia continued for more than 24 h after surgery reduces PMI or in-hospital death. The available databases were searched for randomized controlled trials of epidural analgesia that was extended at least 24 h into the postoperative period. The search yielded 17 studies, of which 11 were randomized controlled trials comprising 1173 patients. Metaanalysis was conducted by using the fixed-effects model, calculating both an odds ratio and a rate difference. Postoperative epidural analgesia resulted in better analgesia for the first 24 h after surgery. The rate of PMI was 6.3%, with lower rates in the Epidural group (rate difference, -3.8%; 95% confidence interval [CI] -7.4%, -0.2%; P = 0.049). The frequency of in-hospital death was 3.3%, with no significant difference between Epidural and Nonepidural groups (rate difference, -1.3%; 95% CI, -3.8%, 1.2%, P = 0.091). Subgroup analysis of postoperative thoracic epidural analgesia showed a significant reduction in PMI in the Epidural group (rate difference, -5.3%; 95% CI, -9.9%, -0.7%; P = 0.04). IMPLICATIONS: Postoperative epidural analgesia, especially thoracic epidural analgesia, continued for more than 24 h reduces postoperative myocardial infarctions. 相似文献
99.
Although exposure of LLC-PK1 epithelial cell sheets to phorbol esters (TPA)
causes a near immediate and total decrease of transepithelial electrical
resistance (TER), continuation of exposure for 3 to 4 days results in a
tachyphylactic response as TER begins to return to control levels. Recovery
of TER is maximal by 5 to 6 days, but reaches only 70 to 80% of control
level. A reciprocal change in the transepithelial flux of D-mannitol
indicates that the TER decrease is indicative of an increase in tight
junction permeability. Exposure of cell sheets to TPA for several days also
results in the appearance of multilayered polyp- like foci (PLFs) across
the otherwise one cell layer thick cell sheets. The pattern of penetration
of the electron dense dye, ruthenium red, from the apical surface, across
the tight junction and into the lateral intercellular space indicates that
the tight junctions of the cell sheet become uniformly leaky after acute
exposure to TPA. However, when exposure is continued for several days, only
the junctions of cells in the PLFs manifest leakiness. The decrease in TER
following acute TPA exposure correlates with the translocation of protein
kinase C-alpha (PKC alpha) into a membrane-associated compartment. With
exposure of several days, only a trace of PKC alpha is visible by Western
immunoblot, and this is in the membrane-associated compartment.
Immunofluorescent microscopy indicates that the trace of PKC alpha seen in
the Western immunoblots is ascribable distinctly to cells of the PLFs.
Monolayer areas between PLFs show no discernible immunofluorescent signal.
The data therefore indicate that tight junction barrier function may be
restored in certain areas by the down regulation of PKC alpha from the
membrane-associated compartment. Failure to down regulate may result in the
paracellular leakiness and abnormal cell architecture of the PLFs. Possible
implications of this model for in vivo epithelial tumor promotion are
discussed.
相似文献
100.
A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters. 相似文献